Develop Reference

How do I install python third party libs on the m1 chip?

The Mac Book Air M1 chip doesn't seem to support pep517 according to the errors of installing third-party libraries with pip or brew. Even using these methods without pep517 downloading the library locally didn't work. How does one circumvent this?
Error from using pip install pandas:
Failed to build numpy
ERROR: Could not build wheels for numpy which use PEP 517 and cannot be installed directly
I've tried this:
pip install <lib>
installing the library locally and trying to install with pip without pep517
brew install <lib>
openblas installation of lib
python env on the intel venv

I had the exact same problem, with a different library but with the same error code for PEP 517, I was using python 3.9 at the time, I checked the docs and found out that it's a problem with the python version for the library, downgraded to Python 3.6 and voila! it worked.
Basically try downgrading to Python 3.6 and check.

Installing python libraries through Anaconda seems to work. I simply downloaded the installer and could later use the libraries globally. If someone has a better in-depth explanation, feel free to comment.

I was having the same message when trying to install a different package. I solved by removing the CommandLineTools and installing it again. The steps were:
sudo rm -r /Library/Developer/CommandLineTools
wait for command prompt...
xcode-select --install
This solved the issue for me.

Pillow is installed, but still getting "ImportError: No module named PIL"

I did find this question asked by few more people, but none of those exactly met my situation, so asking here myself.
I've (rather had) two versions of Python (2.7 and 3.4.3) on my Mac running the latest MacOS High Sierra. As I understand, the v2.7 comes as default installation with the MacOS. And I installed the 3.4.3 (from .dmg file downloaded from the python site). Thus now, the python command defaults to the 2.7, while python3 points to the 3.4.3 in the terminal.
While trying to learn, I tried a python script that uses
import PIL and from PIL import Image
But when running, this gave the error ImportError: No module named PIL.
Upon research on google, I figured out to install PIL and Pillow using
sudo pip install Pillow
It installed correctly, but I'm still getting the same error.
To remove the confusion, I decided to remove the python 3.4.3 from the system. But even after it's removed, I still get the same error.
Even pip list displays Pillow 5.1.0 alright.
So right now, I've only Python 2.7, and the error persists, while Pillow is also in there.
which python gives /opt/local/bin/python as the path.
Does any of the above ring a bell? Any ideas, what else could be missing here?

Phew, finally found the issue. Thanks #Yash for the pointers.
Incidentally I did a which -a python and surprisingly got this output:
/opt/local/bin/python
/usr/bin/python
Damn, I don't remember when I installed a second 2.7 version on the /opt/local/bin folder (probably via macports). Alright, removed the confusion, deleted this python, so now I'm left only with the system installed python at /usr/bin.
And now the imports all run perfectly fine as expected. :-)

Try this,
sudo pip install image
I hope it works! One more thing, do check if you're running python3 filename.py instead of python filename.py, if you want to install it for Python 3, run the command,
sudo pip3 install Pillow

Basic Installation:
pip install Pillow
Windows Installation:
pip install Pillow
Reference: https://pillow.readthedocs.io/en/stable/installation.html

Try this. It worked for me
pip install --upgrade --force-reinstall pillow
If you get something like access denied error run the below command
pip install --upgrade --force-reinstall pillow --user

Python3 is suddenly gone (on macOS) - used it for at least a year

I had python2 installed on my macOS and I parallel installed python3 (without homebrew). It worked perfect and I could use python3 and pip3 from every directory without problems parallel to python and pip for version 2.
Some days ago I did not find pip3 and I had to set an alias to python3 -m ... (I thought I didn't use it before but I had!). Today in the morning I worked with python3 without problems and now python3 got a command not found but I cannot find it on my directories, too.
Where is my python3? And why it is gone?
The only reason I see is that I installed homebrew about a week ago for installing mutt. Is it possible that the brew upgrade function has destroyed paths or even installations?
Would be great to get help from you!
Thanks a lot.

Maybe someone else has the same problem. Therefore the steps for my solution:
the which command shows me the directories of the versions linked everywhere in the system
the argument --version gave me an overview of where I found the different versions of python and vim (for more informations about the directory-changes I checked vim, too)
looking at echo $PATH and ls -lha /etc/paths* I knew more about the current sequence of possible directories of installations and about changes (brew saved the original file as /etc/paths~orig)
with these informations I first upgraded with brew upgrade python3 (it seems that my installed libraries stayed like in the days before the mysterious loss of python3), then I could change the paths and add some alias to get the environment I want to work with
Now everything seems to be like before the problems. If I will notice any further changes I now have the knowledge to solve them within some minutes. Good feeling!
It's not solved why brew downgraded the python3-installation because I'm sure not having installed it in the days of adding python3 to python2. But that isn't very important.
Thanks to the helpers - especially #avigil.

I had the same strange behavior after a brew upgrade: python 3 suddenly disappeared.
brew install python3
told me that
python 2.7.14 is already installed
To upgrade to 3.6.5, run `brew upgrade python`
So that is what I did. The homebrew install of python 2 is gone now, but can be installed again using brew install python#2 .

In case this helps, I had a similar problem where a homebrew upgrade made python3 seem to disappear.
brew install python3
...told me python3 was already installed and just needed to be linked with
brew link python
Ran it, and the symlinks it created seem to have resolved the issue.

How to install Numpy & pip3 for python3.x when they were installed in python2.7? Using Conda?

I want to write program in python3 (3.5), hence I installed python3 next to the pre-installed python2 (2.7) on Mac OS X El Captian.
Since my terminal runs python2.7 by default and Numpy is already installed for it, I put alias python=python3 and expected to be able to install Numpy for python3. when I type pip install numpy. This was the generated message:
Requirement already satisfied (use --upgrade to upgrade): numpy in /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
I also noticed that I have no pip3 even though I am using python3: python --version returned Python 3.5.2, but pip3 install numpy got me -bash: pip3: command not found.
So my questions are:
1) How to install Numpy for python3.x when Numpy is installed on python2.x?
2) How to get pip3?
3) Is it better to use virtual environments, such as Conda, instead of juggling between python2 and python3 on the system?
Thank you from a total n00b
------------------- Update -------------------
Reinstalling python3 also fixed another problem in my case.
When I ran brew doctor, one of the warning message I got was:
Warning: You have unlinked kegs in your Cellar Leaving kegs unlinked can lead to build-trouble and cause brews that depend on those kegs to fail to run properly once built. Run brew link on these: python –
This is a result of me running brew unlink python in order to fix
"Python quit unexpectedly"
when I launch Vim and also
"The ycmd server SHUT DOWN"
Both seem to relate to the YouCompleteMe autocomplete plugin which I downloaded for Python.
I got my idea of removing symlinks from here and here
However, Homebrew evidently did not like the absence of those 39 symlinks.
After uninstall (brew uninstall python3) and then re-install python3 (brew install python3) as Toby suggested, Homebrew gave me
You can install Python packages with
pip3 install <package>
Then when I pip3 install numpy and pip3 install scipy, both executed successfully.
To my surprise, symlinks created during Python installation used to cause aforementioned error messages for Python and YouCompleteMe, but now I open python files using Vim without crash from a fresh Python installation, which definitely created the symlinks.
------------------- Update2 ------------------
After re-installing Anaconda2, the same YouCompleteMe error came back. I suspect Anaconda messed up symlinks.

I would recommend using the Anaconda Python distribution.
The main reasons are as such:
You will have a Python distribution that comes with numpy and the rest of the Scientific Python stack.
The Anaconda Python will be installed under your home directory, with no need for sudo-ing to install other packages.
conda install [put_packagename_here] works alongside pip install [put_packagename_here]; conda install is much 'cleaner' (IMHO, differing opinions are welcome).
If you have a Python 3 environment as your default, then pip works out-of-the-box without needing to remember to do pip3.
conda environments are easier to manage than virtualenv environments, in my opinion. And yes, you can have Python 2 alongside Python 3.
I once messed up my system Python environment - the one that came with my Mac - and it broke iPhoto (back in the day). Since then, I became convinced of needing separate, atomic environments for different projects.
I've detailed more reasons in a personal blog post.
Other distributions, of course, are all good, provided they give you what you need :).

The simplest way on a Mac is with Homebrew:
http://brew.sh/
Install Homebrew, then run:
brew install python3 pip3
Edit --
Python3 includes pip3, but Homebrew occasionally has trouble linking to the correct versions, depending on what has been installed. Running the following command:
brew doctor
And if you see errors relating to python or unlinked kegs, try running:
brew uninstall python python3
And reinstalling after checking brew doctor.
https://unix.stackexchange.com/questions/233519/pip3-linked-to-python-framework-instead-of-homebrew-usr-local-bin

pip install matplotlib fails on mavericks with homebrew

I am trying to install the Scipy python stack, but having issues.
I have a new mac os with mavericks (10.9).
I have installed homebrew and am using brew to manage installations.
I used
% brew install python
then (I verified pip is from my homebrew installation)
% pip install numpy [this works]
% pip install scipy [this works]
% pip install matplotlib OR pip install http://downloads.sourceforge.net/project/matplotlib/matplotlib/matplotlib-1.3.1/matplotlib-1.3.1.tar.gz
Both fail with the same error. After checking the backend, I get
Fatal Python error: PyThreadState_Get: no current thread
The error message from mac os X (the pop up error window) shows errors very similar to those in the previous thread
Homebrew + Python on mac os x 10.8: Fatal Python error: PyThreadState_Get: no current thread importing mapnik
It seems I need to fix the python bindings, as some of them linked against the /System/Library python that ships with the mac. What is not clear to me from the above post is
which of the Binary Images need to be "re-linked"? all of them? some seem quite general an not related to matplotlib
how do I actually use install_name_tool to fix the link? As I mentioned, some seem quite general - do I really want to change the path? Do I cp the dylib from old to new?
I have also tried
brew uninstall python
and re-brewing, all to get the same error. I am trying not to use EPD because EPD installs its own libxml2 and others, which I need for other software I will install, and this has caused me problems on an old machine. I am open to considering a virtualenv, but was hoping to learn to just fix my current problem if possible.
Thanks,
Andre
PS, when pip install matplotlib`, the following warning appears, which seems odd because matplotlib is such a staple piece of software
You are installing an externally hosted file. Future versions of pip will default to disallowing externally hosted files.
You are installing a potentially insecure and unverifiable file. Future versions of pip will default to disallowing insecure files.

This is an issue in pygtk. You can test it with brew (it should throw the same error):
brew test pygtk
I ran into the same problem, and got past that error with the following steps from https://github.com/mxcl/homebrew/issues/13654
brew rm py2cairo
brew install py2cairo
You can test that pygtk is working using brew test pygtk again.
I'm still having other problems getting pip install matplotlib to work, so you may also run into more problems, but that should get you past that particular issue.

I had the same problem, and after some experimentation it seems that installing under Python 3 works more reliably. i.e. this installed without error:
pip3 install matplotlib
I then had to re-install everything else using pip3, and make sure I was running under python3 at execution time.

brew install freetype
it works on mac os sierra!